Introduction to Supervisor Process Management Tool and Installation Guide

Supervisor is a Python‑developed client/server daemon for Linux/Unix that provides process management capabilities such as monitoring, starting, stopping, and restarting one or multiple processes, automatically relaunching them if they unexpectedly terminate; it does not support Windows.

Without a daemon, three problems may occur: (1) PHP applications run inside a shell and are terminated when the shell closes, causing service outage; (2) If a PHP process crashes, manual shell intervention is required to restart it, often not timely; (3) After a server crash or reboot, processes must be manually started again.

To solve these issues, a program is needed to monitor PHP applications and immediately restart them when they stop.

Installation and configuration steps:

1. Install the Python package manager:

yum install python-setuptools

2. Install Supervisor:

easy_install supervisor

3. Create the Supervisor configuration directory and generate the default configuration file:

mkdir /etc/supervisor
echo_supervisord_conf > /etc/supervisor/supervisord.conf

Append the following to the end of supervisord.conf to include additional configuration files:

;[include]
;files = relative/directory/*.ini

;conf.d is the directory for configuration files and must be created manually
[include]
files = conf.d/*.conf

4. Create a program‑specific .conf file under /etc/supervisor/conf.d/ . Example for a .NET service named MGToastServer :

[program:MGToastServer] ; program name
command=dotnet MGToastServer.dll ; command to run the program
directory=/root/文档/toastServer/ ; working directory
autorestart=true ; restart automatically if it exits unexpectedly
stderr_logfile=/var/log/MGToastServer.err.log ; error log file
stdout_logfile=/var/log/MGToastServer.out.log ; output log file
environment=ASPNETCORE_ENVIRONMENT=Production ; environment variables
user=root ; user to run the program
stopsignal=INT

5. Start Supervisor and verify that the program is running:

supervisord -c /etc/supervisor/supervisord.conf
ps -ef | grep MGToastServer

6. Configure Supervisor to start on boot by creating a systemd service file supervisord.service :

# dservice for systemd (CentOS 7.0+)
# by ET‑CS (https://github.com/ET‑CS)
[Unit]
Description=Supervisor daemon

[Service]
Type=forking
ExecStart=/usr/bin/supervisord -c /etc/supervisor/supervisord.conf
ExecStop=/usr/bin/supervisorctl shutdown
ExecReload=/usr/bin/supervisorctl reload
KillMode=process
Restart=on-failure
RestartSec=42

[Install]
WantedBy=multi-user.target

Copy the file to /usr/lib/systemd/system/supervisord.service , enable it, and verify:

systemctl enable supervisord
systemctl is-enabled supervisord

7. Common Supervisor control commands:

supervisorctl restart
; restart a specific app
supervisorctl stop
; stop a specific app
supervisorctl start
; start a specific app
supervisorctl restart all                  ; restart all apps
supervisorctl stop all                     ; stop all apps
supervisorctl start all                    ; start all apps